The present invention relates to ventilators, more particularly but not exclusively for use in rooms with sealed windows and/or double glazing where it is desirable to provide ventilation without having to open the window. This type of ventilation is now usually referred to as "secondary ventilation".
Secondary ventilation is often achieved by the insertion of a slot ventilator into a slot cut or formed in the sash of a window. Airflow through the resultant ventilation passage between the interior and exterior of the building is controlled by some sort of openable and closeable ventilator such as a hit and miss ventilator or a parallel motion ventilator of the type described in UK patent 1417751. In situations where the "throw" of the ventilator, in other words the distance forward of the main ventilator body by which the facing strip or closure member has to be moved in order fully to open the ventilator, needs to be small, a parallel motion ventilator of the type shown in PCT publication WO 09/08927 may be used.
In a typical arrangement, a slot ventilator has a pair of parallel side plates which in use are positioned within the slot in the window, between which is mounted the pivoting mechanism enabling the facing strip or closure member to be moved between its open and closed positions. At the forward edge of these side plates (that is in use, at the inside of the slot) there is a mounting flange. This acts both to provide a surface against which the facing strip or closure member can seal in its closed position, and also the means by which the ventilator is actually secured to the window. Typically, screw holes are provided at each side of the flange so that the ventilator can be screwed to those parts of the window at the opposite sides of the slot.
A difficulty with this sort of arrangement is that sufficient space has to be provided adjacent the inner end of the slot both to enable the ventilator to be inserted in the slot, and for it to be secured by means of its flange at either side of the slot.